PMN Crop News Homepage   

Posted 29 August 2006. PMN Crop News.

USDA Laboratory Confirms Plum Pox Virus in Michigan


Washington, DC (August 11, 2006) – The U.S. Department of Agriculture’s National Plant Germplasm and Biotechnology Laboratory in Beltsville, Md., today confirmed the presence of the plum pox virus (PPV) on a plum tree sample from Southwestern Michigan.

Plum pox is a viral disease of stone fruit species that first appeared in the United States in Pennsylvania in October 1999 and most recently in New York in July 2006. The plant virus does not pose any human health risks. This virus is also found in Canada.

The plum tree sample was collected at the Southwest Michigan Research and Experiment Center (SWMREC), a Michigan State University facility, located near the Benton Harbor-St. Joseph area. The samples were collected as part of state surveillance surveys and underwent preliminary testing at the Michigan Department of Agriculture where researchers obtained positive results.

The plum pox strain identified in Michigan is the D strain of the virus--the same strain that is present in Canada, Pennsylvania and New York. The D strain of the virus is less virulent than other strains, does not infect cherry trees and is not seedborne. Because the strain is not seedborne, it is not necessary to regulate the movement of fruit to prevent the spread of the disease.

The Michigan Department of Agriculture, in cooperation with APHIS, has conducted extensive surveys for PPV since 2000. Survey specialists are currently surveying all 14,000 host trees at the SWMREC facility. Following the completion of this survey, APHIS and MDA will expand surveillance efforts to include host trees within two miles of the center.

PPV is the cause of a serious plant disease, affecting a number of species, including peach, nectarine, apricot and plum. Several aphid species can serve as carriers of the virus. The virus stays viable in the aphid’s mouthparts for a period of approximately one hour and most aphids can generally transmit infection several hundred meters from the initial source plant.


Melissa O'Dell
(301) 734-5222

Bridget Beckman
(517) 373-1104